1. Field of the Invention
The present invention relates to a secondary battery and a power storage system using a secondary battery. The present invention relates to a system having a function of recovering a secondary battery from its deteriorated state.
2. Description of the Related Art
In recent years, a variety of power storage devices such as lithium-ion secondary batteries, lithium-ion capacitors, and air batteries have been actively developed. In particular, demand for lithium-ion secondary batteries with high output and high energy density has rapidly grown with the development of the semiconductor industry, for electrical devices, for example, portable information terminals such as mobile phones, smartphones, and laptop computers, portable music players, and digital cameras. The lithium-ion secondary batteries are essential as rechargeable energy supply sources for today's information society.
If power supply equipment malfunctions or is partly broken or an electric power company stops or reduces power supply because of natural disasters (e.g., crustal alteration such as earthquakes and ground subsidence, typhoons, and lighting strikes), terrorism, accidents, or the like, for example, not only social life but also personal lives can be significantly influenced. Thus, demand of home-use power storage devices that can provide electric energy by individuals has been increasing.
A lithium-ion secondary battery includes at least a positive electrode, a negative electrode, and an electrolytic solution (Patent Document 1).